The invention relates to a cutter support body for high speed cutting heads for woodworking.
Cutting heads for woodworking consist of a cylindrical support body provided at its circumference with at least two axially extending recesses, which are arranged in radial symmetry for the reception of cutter blade supports. The cutter blade supports disposed in these recesses consist generally of a backplate and a pressure member between which a hard metal cutter blade is firmly engaged in a form-locking manner and clamped by clamping screws which extend through threaded bores in the support body and engage the pressure member.
During woodworking, the cutting speed is relatively high and there is a trend to even higher speeds. Because of the high centrifugal forces generated in the process and the corresponding strain on the cutting head support body, however, the possible cutting speed is limited. For safety reasons cutting heads for operation at high speed require approval by an agency. Such approval is given on the basis of a test with an operating speed, which exceeds the design operating speed by 50%. It must be shown that there is no reaction to such an excessive speed which would appear to make even the slightest loosening of the engaged cutting blades or the cutting blade mounting structure possible. In this way, it is to be made sure that the cutting blades and mounting structure are not thrown outwardly during the high operation speeds.
With present designs, speeds of, for example, 12,000 rpm were not admissible. The deep radial recesses formed into the support body for the reception of the cutting blade mounting structures and the fact that the side walls of the recesses are forced apart in the circumferential direction by the clamping forces results, at higher speeds, in motion reactions of the cutting head body whereby the recesses are widened in circumferential direction, which is not acceptable.
It is therefore the object of the present invention to provide a cutting blade support body which can be employed for high speed applications at rpms which were not reachable so far.
In a cutting blade support body for a wood working cutting head including a cylindrical support body with at least two recesses disposed in axial symmetry and extending over the full axial length of the cylindrical support body for receiving and supporting hard metal cutting blades, an annular plate is mounted on each end face of the cylindrical support body and extends over the axial ends of the recesses so as to radially fully cover the recesses and contain the cylindrical support body when exposed to high centrifugal forces.
The annular blades cutting blade provided at opposite sides of the support body stiffen the support body in circumferential direction.